Current knee arthroplasty tibial implants that retain the tibial eminence contain a straight sagittal wall portion which banks against the eminence. Typically, the sagittal wall resection of the eminence corresponding to the straight sagittal wall of an implant is made with a reciprocating saw normal to the transverse tibial resection plane. When placing an eminence-preserving implant, preferences to component placement on a cut plane include avoiding ligaments, optimizing bony coverage, avoiding deep cuts into the eminence, and permitting possible kinematic trialing feedback, for example.
However, a straight walled implant may not be the most optimal design to retain constant resection depth on both sides of the eminence and to avoid ligaments because the native eminence wall itself is not a perfectly straight line. A straight walled implant also may not provide sufficient anterior-posterior stability.